Theory of differential current switches and logic design of ternary ECL circuits at switch level
Xunwei Wu, Zhang Zhuan · International Journal of Electronics · 1991
Starting from the viewpoint that the switch states and signal values in a digital circuit should be described separately by two different kinds of variable, the interaction between the switching element and signal in multi-valued ECL circuits is analysed and two types of connection operations, threshold switching operation and current switching operation, are proposed. The properties and circuit realizations of these new operations are discussed and the theory of differential current switches applicable to ECL circuits is established. Examples of basic ternary ECL circuits confirm that this theory can effectively guide the logic design of ternary ECL circuits at switch level. The circuits are verified by using the SPICE II program. They have the same logic level difference and transient characteristic as binary ECL circuits. Since the multi-valued ECL circuit uses only one set of power supply and can set several threshold values by using reference levels, it can be fabricated using conventional ECL techniques and is compatible with binary ECL circuits.